长江三角洲地区土壤环境质量与修复研究 Ⅱ.典型污染区农田生态系统中二(口恶)英/呋喃(PCDD/Fs)的生物积累及其健康风险

对长江三角洲地区某典型污染区农田生态系统和部分农产品中多氯代二苯并二(口恶)英(PCDDs)/呋喃(PCDFs)的污染特征、生物富集及潜在健康风险进行了初步研究.结果表明,该地区局部农田土壤中PCDD/Fs含量及毒性当量平均达556 pg g-1dw和TEQ 20.2pg g-1 dw,已在不同农产品中明显积累,其中稻米中PCDD/Fs含量及毒性当量为50.7pg g-1 dw和TEQ 6.4 pg g-1 dw,蔬菜茎叶中为35.2 pg g-1 dw和TEQ 6.7 pg g-1 dw;当地家禽鸡肉中PCDD/Fs含量及毒性当量为30.9pg g-1 ww和TEQ 5.7pg g-1 ww.日允许摄入量(TDI)计算结果表明,经稻米-蔬菜、稻米-蔬菜-鱼腥草、稻米-蔬菜-鱼腥草-鸡肉三种暴露途径至人体的PCDD/Fs日摄入量分别为TEQ 67.4、72.1、83.5 pg kg-1 d-1,均远远超过世界卫生组织(WHO)制定的TDI标准(TEQ 1～4pg kg-1 d-1).该地区局部农田生态系统及部分农产品中存在二(口恶)英类(PCDD/Fs)污染,已构成较大的人体健康风险.     

长江三角洲地区土壤环境质量与修复研究I.典型污染区农田土壤中多氯代二苯并二噁英/呋喃(PCDD/Fs)组成和污染的初步研究

通过同位素稀释高分辨率气相色谱-质谱方法(HRGC/HRMS)对长江三角洲地区某典型污染区农田土壤中多氯代二苯并二英(PCDDs)/呋喃(PCDFs)组成、含量及毒性当量进行了初步研究。结果表明,该地区农田土壤中PCDD/Fs总含量的平均值达2639·1pgg-1dw,并检测出PCDD/Fs的四氯~八氯多种异构体。根据世界卫生组织毒性当量(TEQ,哺乳动物)计算结果显示,农田土壤中PCDD/Fs的毒性当量为TEQ20·8~21·3pgg-1dw,超过加拿大国家居住环境土壤二英含量控制标准的5倍多,其中2,3,4,7,8-PCDF和1,2,3,7,8-PCDD对PCDD/Fs的TEQ值贡献最大。该地区农田土壤中已经出现一定程度的二英/呋喃污染。     

长江三角洲地区土壤环境质量与修复研究 Ⅱ.典型污染区农田生态系统中二噁英/呋喃(PCDD/Fs)的生物积累及其健康风险

对长江三角洲地区某典型污染区农田生态系统和部分农产品中多氯代二苯并二嘿英（PCDDs）／呋喃（PCDFs）的污染特征、生物富集及潜在健康风险进行了初步研究。结果表明，该地区局部农田土壤中PCDD／Fs含量及毒性当量平均达556 pg g^-1dw和TEQ 20．2 pg g^-1dw，已在不同农产品中明显积累，其中稻米中PCDD／Fs含量及毒性当量为50．7 pg g^-1dw和TEQ6．4 pg g^-1dw，蔬菜茎叶中为35．2 pg g^-1dw和TEQ6．7 pg g^-1dw；当地家禽鸡肉中PCDD／Fs含量及毒性当量为30．9 pg g^-1ww和TEQ5．7 pg g^-1ww。日允许摄入量（TDI）计算结果表明，经稻米-蔬菜、稻米-蔬菜-鱼腥草、稻米-蔬菜-鱼腥草-鸡肉三种暴露途径至人体的PCDD／Fs日摄入量分别为TEQ67．4、72．1、83．5Pg kg^-1d^-1，均远远超过世界卫生组织（WHO）制定的TDI标准（TEQ 1-4pg ks^-1d^-1）。该地区局部农田生态系统及部分农产品中存在二嘿英类（PCDD／Fs）污染，已构成较大的人体健康风险。     

白银市不同功能区表层土壤中PCDD/Fs分布特征研究

采用高分辨气相色谱高分辨质谱联用仪（HRGC/HRMS）对白银市不同功能区土壤样品中的17种2,3,7,8-PCDD/Fs的含量进行了测试,探讨了白银市典型区域表层土壤中PCDD/Fs的来源、分布特征。结果表明,白银市各类表层土壤中17种2,3,7,8-PCDD/Fs的I-TEQ浓度范围为0.42～8.56pg（I-TEQ）·g-1,均值为2.28pg（I-TEQ）·g-1,其中,工业区土壤中PCDD/Fs含量为0.42～8.56pg（I-TEQ）·g-1,均值为3.37pg（I-TEQ）·g-1;城市生活区PCDD/Fs的含量为0.50～1.83pg（I-TEQ）·g-1,均值为1.31pg（I-TEQ）·g-1;农业区含量为0.49～1.33pg（I-TEQ）·g-1,均值为1.01pg（I-TEQ）·g-1;两个背景点PCDD/Fs的含量分别为0.60和1.10pg（I-TEQ）·g-1。研究区域内PCDD/Fs的含量呈现工业区〉城市生活区〉农业区〉背景区的趋势,高氯代的PCDD/Fs异构体对土壤中二恶英毒性当量的贡献率较大。     

白洋淀鱼类体内多氯联苯积累特征及其毒性评价

针对持久性有机污染物在水生生物体内易于积累的特性,利用气相色谱与质谱联用技术（GC-MS）,检测了白洋淀8种鱼类体内多氯联苯（PCBs）含量,并分析了同系物组成特征。根据白洋淀鱼类检测到同系物情况,计算毒性当量（TEQ）并进行评价。白洋淀8种鱼类体内PCBs平均含量范围是55.85~1 485.74 ng.g-1脂肪重,从高到低的顺序依次为黄颡〉黄鳝〉乌鳢〉泥鳅〉鲤鱼〉鳙鱼〉鲫鱼〉鲇鱼。在8种鱼类PCB同系物组成中,四氯联苯和五氯联苯是主要的同系物,其相对百分含量为52.0%~84.3%。这种组成模式反映了白洋淀地区有多氯联苯工业品的使用历史。8种鱼类体内PCBs的毒性当量（TEQ）范围是0.09~1 412.87 pg TEQ.g-1脂肪重,其大小顺序依次为鳙鱼〉鲫鱼〉鲇鱼〉黄颡〉黄鳝〉鲤鱼〉乌鳢〉泥鳅。结果表明,白洋淀淀区部分鱼类已经受到PCBs一定程度的污染,应引起重视。     

广西桂中南部地区富硒土壤硒含量及其与土壤理化性状的关系

为了解广西桂中南部地区富硒土壤的硒含量及其分布特征,明确土壤硒与主要土壤性状指标的关系,选择水田和旱田,分别于0～20 cm和150～200 cm深度取样,测定土壤全硒含量及主要理化性状。结果表明,桂中南部地区农田表层土壤(0～20 cm)全硒平均含量(算术平均值)为0.77μg g-1,93.76%的农田表层土壤属于富硒土壤(0.4～3μg g-1),深层土壤(150～200 cm)全硒平均含量为0.62μg g-1,79.04%的深层土壤属于富硒土壤,研究区内的表层和深层土壤全硒都达到足硒标准(0.175～3.000μg g-1)。广西桂中南部研究区内农田土壤硒含量与土壤的Al2O3、Fe2O3、有机碳呈正相关,与pH值呈负相关,旱地土壤相对于水田土壤富Al2O3、Fe2O3、有机质,低pH值,导致旱地土壤的硒含量高于水田土壤。据此表明,广西桂中南部地区农田土壤有利于种植富硒作物。     

饲料中二噁英赋存特征及其向养殖动物体内迁移规律

二噁英(Polychlorinated dibenzo-p-dioxins and dibenzofurans, PCDD/Fs)因其高毒性、蓄积性、持久性和长距离迁移特性而备受全球关注。由于二噁英容易沿着食物链富集放大,因此,饲料中二噁英极容易在养殖动物体内富集并对动物产生健康风险。本文在国内外最新研究基础上,总结并探讨饲料中二噁英的赋存现状以及其向养殖动物的迁移和蓄积规律,旨在对饲料和养殖动物二噁英的管控提供科学支持。     

丹江口水库淅川淹没区农田土壤中有机氯农药的分布特征及生态风险研究

采集了丹江口淅川淹没区高程在170 m以下8个乡镇的农田土壤共18个样品,采用索氏提取分离富集、气相色谱-电子捕获（GC-ECD）检测、气相色谱仪-质谱（GC-MS）确证的方法对样品中20种有机氯农药进行了分析,研究了丹江口水库淅川淹没区土壤中OCPs的分布特征与潜在风险。结果表明,研究区农田土壤中有α-HCH和DDE两种有机氯农药被检出,其中α-HCH含量范围是nd～107.55 ng·g-1,平均值为40.31 ng·g-1;DDE含量范围是1.42～237.56 ng·g-1,平均值为36.28 ng·g-1。总有机氯含量范围为15.16～279.93 ng·g-1,平均值为76.59 ng·g-1;与其他地区比较,ΣHCHs含量偏高,ΣDDTs含量相当;α-HCH可能来自早期残留,也可能来自大气沉降,DDE可能源自早期残留。淅川淹没区农田土壤中α-HCH和DDE含量基本上符合国家土壤环境质量标准一级标准,土壤质量良好,但仍然存在一定的生态风险。     

酶联免疫法快速筛查牛奶中的二噁英

二噁英是最受人们关注的持久性有机污染物之一。本研究建立了ELISA快速筛查牛奶基质中二噁英的检测方法。牛奶样品经真空冷冻干燥,加速溶剂萃取法萃取、用酸性硅胶柱、活性炭柱净化后,浓缩氮吹后复溶,进行ELISA检测。结果表明,方法回收率为72.0%~125.2%,相对偏差<30%。本法对牛奶中二噁英毒性当量(TEQ)测定值与高分辨气相色谱-高分辨质谱法(HRGC-HRMS)测定值吻合度高,检测结果误差<20%。本方法具有操作简便、快速、检测结果可靠等特点,适用于基层检测机构对牛奶中二噁英的快速筛查。     

多氯联苯污染农田土壤的细菌群落结构差异及其影响因素

应用PCR-DGGE技术分析多氯联苯长期污染农田土壤的细菌群落结构,并主要运用统计学方法探讨了多氯联苯总量和土壤理化因子对细菌群落结构的影响。结果显示:不同水平多氯联苯污染农田土壤中细菌群落结构存在差异,较高水平多氯联苯(64.0~484.5 ng g-1dw)污染土壤的细菌群落结构较为接近;相对于其他土壤理化因子(如有效磷、pH、有机质等),多氯联苯显著影响农田土壤中的细菌群落结构(p<0.05)。这表明在多氯联苯胁迫下土壤细菌整体群落结构发生改变,提示多氯联苯污染对土壤微生物生态的影响,这可能导致土壤生态环境质量发生变化,是潜在的生态风险因素。     

土壤侵蚀研究回顾与展望

本文概述了建国40年来土壤侵蚀研究的成就，以及在国民经济建设中的地位和作用。讨论了需要进一步研究解决的问题。诸如：查明水土流失和水土保持现状；土壤侵蚀量预报；自然侵蚀与人为加速侵蚀评价；土壤侵蚀过程和生态环境演变；土壤侵蚀-土壤生产力反应模型；水土流失区的整治开发与大江大河治理及发展农林牧生产的关系。     

VARIATIONS IN SULPHUR AND NITROGEN FOLIAR CONCENTRATION OF DECIDUOUS AND CONIFERS VEGETATION IN SLOVAKIA

The foliage contents of S_total and N_total were determined in 405 Permanent monitoring plots in four National Parks and sixteen Landscape Protection Areas and were compared with 1483 Permanent monitoring plots on Slovakia. The foliage content of S ranged from 0.72 to 6.77 g kg^-1 in hardwoods and from 0.98 to 4.3 g kg^-1 in softwoods. A critical increase was determined in one National Park and in four Landscape Protection Areas. The foliage content of N ranged from 9.7 to 48.7 g kg^-1 in softwoods, and from 7.8 to 51.4 g kg ^-1 in hardwoods. An insufficient level of N was determined in one Landscape Protection Area and a critical increase in four Landscape Protection Areas. The sulphur to nitrogen ratio ranged from 0.08 to 0.176 in softwoods, and from 0.078 to 0.253 in hardwoods. The foliage surface on hitherto explored four National Parks and sixteen Landscape Protection Areas in network 4 × 4 km was covered by all categories of rigid fall-out particles. Fly-ash from coal combustion were observed each of National Parks and Landscape Protection Areas by scanning electron microscopy. Mycelia and spore, mineral matters, sand and soil particles were present on all National Parks and Landscape Protection Areas. Particles derived from aluminium production were observed at three Landscape Protection Areas. Particles derived from cement production and from lime works were observed at two National Parks and six Landscape Protection Areas. Particles derived from ferrous metals industry were observed at each of National Parks and Landscape Protection Areas and particles typical for other technologies were present in three of National Parks and twelve Landscape Protection Areas.     

IODINE IN SOIL PROFILES IN RELATION TO IRON AND ALUMINIUM OXIDES AND ORGANIC MATTER

The iodine content in successive 10 cm horizons of eighteen soil profiles from England and Wales was determined and correlated with contents of‘free’ aluminium and iron oxides (oxalate-soluble) and organic matter. The pattern of change in iodine content with depth varied considerably with soil type. In the rendzina soils, the content was relatively high in the surface 10 cm but declined markedly with depth. In the podsols, iodine was low at the surface but increased in the B horizon: in one of these soils an iron pan of about 1 cm thickness had an iodine content as high as 37.6 mg/kg. In two soils derived from Ordovician, and one from igneous, rock material, the iodine content was relatively high (up to 25 mg/kg) with maximum values at intermediate depths. In contrast, soils derived from river alluvium and from lowland clays generally had low iodine contents (< 6 mg/kg) which showed little variation with depth in the profile. In a peat soil the iodine content was relatively high in the horizons above 60 cm but was low (1. 3 mg/kg) in the underlying clay. In all 154 samples from the eighteen sites, iodine content was closely correlated with oxalate-soluble aluminium (r= 0.834***) but not with oxalate-soluble iron (r= 0. 35) or organic matter (r= 0.37). However, in the five most acidic soils, with pH below 4. 8, the iodine content was more closely correlated with iron than with aluminium.     

SOIL AND WATERCONSERVATION IN CHINA

Present Status and Suggestions on Establishing Soil and Water Conservation Sci-Tech Zones of Sichuan；Some Cognition on Establishing a Big Pilot Area of Soil and Water Conservation in Guang‘an；Ecological Effect of Long-Term Fertilizer Applied Soil；Existing Problems in Applying Poplar into Soil and Water Conservation and Countermeasures;Preliminary Approach to Soil and Water Conservation Modes in Various Kinds of Open Economic Zones and Small Reskdential Districts in Dazhou City.     

NITRATE IN LEAF PETIOLE AND BLADE OF SPINACH CULTIVARS AND ITS RELATION TO BIOMASS AND WATER IN PLANTS

A pot experiment was carried out, with 30 spinach cultivars to determine nitrate accumulation in leaf blade and petiole, and its relationship to biomass and water in plants. Results showed that the fresh weight proportion of blade to shoot was higher than that of petiole. Furthermore, a higher positive correlation was found between fresh weights of blades and shoots than that of petioles and shoots. Unlike biomass, nitrate-nitrogen (N) concentration and total amount of nitrate-N accumulated in petiole were significantly higher than those in blade, and petiole was obviously the main organ for nitrate accumulation. Differences of nitrate-N concentration in petiole and the observed positive correlation between nitrate-N concentrations in petioles and shoots were more significant than that in blades and shoots. Nitrate-N concentration in petiole was also significantly correlated with fresh and dry shoot weight and total amount of water in shoots. However, this relationship was not found for blade.     

海南砖红壤的微形态特征以及南方网纹红土与砖红壤环境意义的差异

主要运用土壤微形态学、粘土矿物学和土壤化学方法,对海南岛三个不同母质的砖红壤剖面的微形态特征和成壤过程进行研究,并将网纹红土和砖红壤进行比较.结果表明,砖红壤典型的微形态特征为易风化矿物颗粒和粘粒胶膜的缺失、均质状的b-垒结以及风化成因铁锰质结核的出现;典型的成壤过程为强烈的化学风化、红化、均质化、淋溶以及显著的脱硅富铝化过程.随着成土母质和土壤排水条件的变化,砖红壤的微形态特征亦有所差异.而我国南方的网纹红土的发育程度低于砖红壤,不宜被划分为砖红壤或氧化土,而更趋向归入老成土,在我国土壤发生学分类中大致相当于红壤.     

春秋季红壤旱地氨挥发对氮施用量、气象因子的响应

通过红壤旱地种植牧草马唐和蔬菜冬萝卜轮作试验,研究了在春秋二季红壤旱地氨挥发对不同施氮量和气象因子的响应。结果表明,红壤旱地春季牧草实验,氮肥处理N90、N160和N230,氨挥发持续10~17d,在施肥后6~8d达到峰值,峰值(扣除对照N0)分别为N0.11、0.57和1.84kghm-2d-1。秋季氮肥处理N70、N130、N190和N250以基肥和以水带肥追施(基/追比为7∶3)氨挥发持续时间均为10~11d,基肥氨挥发峰值(扣除对照N0)分别为N0.02、0.05、0.06kghm-2d-1和0.09kghm-2d-1;追肥氨挥发峰值(扣除对照N0)分别为N0.05、0.22、0.38kghm-2d-1和0.72kghm-2d-1。不同施氮处理,春季累计氨挥发量为N0.67~5.16kghm-2,占施入肥料N的0.74%~2.24%;秋季累计氨挥发量为N0.37~3.04kghm-2,占施入肥料N的1.31%~3.69%。红壤旱地春秋二季氨挥发量(y)均随施N量(x)的提高而指数递增,其关系式分别为:y=0.1576e0.0146x和y=0.1826e0.0112x。显著性检验表明,春秋两季不同施氮量处理之间,土壤氨挥发量及挥发通量差异均达到显著水平。春秋二季基肥氨挥发总量和通量均与气温、气压、蒸发量和土温等环境气象因子有较好的相关性(p<0.05)。     

江西省兴国县、余江县土壤侵蚀时空变化研究

利用遥感技术与地理信息系统技术的结合 ,对江西省兴国县和余江县的土壤侵蚀状况进行了时空变化研究。研究结果表明 ,兴国县和余江县的土壤侵蚀状况 ,在侵蚀面积和程度上 ,都在明显改善 ;两县土壤侵蚀面积百分数的缩小量几乎相等 ,但兴国县缩小的比例较余江县小。但就总的情况看 ,土壤侵蚀仍是一个突出问题 ,值得重视     

红壤旱地和稻田土壤中有机底物的分解与转化研究

^14 C标记葡萄糖和稻草为底物,室内培养法研究在相同水分条件下,红壤旱地和稻田土壤中新鲜有机物的分解与转化的差异,以及对土壤原有有机碳矿化的影响.在100 d内葡萄糖^14C在旱地和稻田土壤中的累积矿化率分别为49.6%和46.7%,稻草^14C为25.2%和21.8%;两种底物对土壤原有有机碳分解产生的＂激发效应＂和对土壤微生物生物量碳（BC）的影响均以旱地土壤大于稻田土壤.在旱地和稻田土壤中葡萄糖^14C转化为土壤BC的最大比率分别为23.5%和21.6%,稻草^14C分别为10.4%和11.3%.根据添加^14C标记葡萄糖处理中^14C标记微生物生物量碳（14C-BC）的变化,得到旱地和稻田土壤BC的周转时间分别为329 d 和127 d.这些结果表明在含水量为45%饱和持水量（WHC）条件下,有机底物在旱地土壤中的分解快于稻田土壤,但稻田土壤BC的周转速率快于旱地土壤.     

AMMONIUM AND NITRATE IN SOIL AND RATOON SUGARCANE GROWN IN FUNCTION OF NITROGEN ON OXISOL

After harvest, sugarcane residues left on the soil surface can alter nitrogen (N) dynamics in the plant-soil system. In Oxisols, the nitrogen fertilizer applied had its effects on the levels of ammonium and nitrate in the soil, N concentration in the plant leaves, and on the growth and productivity of second ratoon plants. The N rates tested were of 0, 60, 120, 180, and 240 kg ha^?1. Each treatment was replicated four times. Four months after the experiment was started, ammonium and nitrate concentration in the soil, N levels in plant leaves, and plant growth were evaluated. Productivity was evaluated 11 months after the experiment was set. By increasing the content of mineral N in soil, plant growth variables reflected differences in the production of stems; however, it did not affect foliar N. The use of leaf analysis was not important to assess the nutritional status of nitrogen in the ratoon sugarcane. Nitrogen concentration in soil was affected by nitrogen fertilization, but not the N content in leaves. The rate of 138 kg N ha^?1enabled greater production of sugarcane stalks (140 t ha^?1).